<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <div id="div1">
        <div id="div2">
            <div id="div3">
            </div>
        </div>
    </div>
    <script src="yss.js" defer></script>
</body>
</html>